Appropedia shares knowledge to build rich, sustainable lives (read our vision and mission).

Explore 8,639 resources and solutions for sustainability, appropriate technology, poverty alleviation, permaculture and more!

  • Climate change
  • Culture and community
  • Design
  • Energy
  • Environment
  • Environment rehabilitation
  • Food and agriculture
  • Fundamental human needs
  • Health and safety
  • International development
  • Knowledge
  • Transport
  • Water
  • Medical skills

Get started editing Advanced search Browse categories


850+ citations of Appropedia
Appropedia is used by academics as a source of knowledge all over the world. See a list of articles here.

Community Action for Sustainability News

  • Climate change: Biggest global poll supports 'global emergency', Jan 27 ...Climate news 2021
  • “Doughnut Economic” model arrives in California, Jan 26
  • New Global Coalition launched to address impacts of Climate Change, Jan 25 ...UK Climate news 2021
  • "There is no Planet B" has been updated, ready for the moment. And there may be some movement towards climate hope, Jan 22 ...UK Climate news 2021
  • A new landscape for skill-sharing emerges from pandemic aftermath, Jan 7, 2021 ...Sharing news

Selected page

Fixed dome digester

Biofuel is a term used to describe fuel sources that are derived from easily regeneratable animal or plant-based resources. Biofuels are categorically different from fossil fuels, as biofuel production is not based on the anaerobic decomposition of buried organic matter. Furthermore, fossil fuel deposits take millions of year to form and are a naturally occurring phenomenon while resources for biofuel production are usually considered renewable and are typically representative of the bi-product from some other production process. Biofuels are thus a form of closed-loop recycling recycling, as the waste product from some production process is re-appropriated in to fuel for the process itself. It should be noted that although biofuels vary greatly in nature from fossil fuels, they are both a form of indirect solar energy; the initial energetic input stored in these fuels originated from the sun and was captured via terrestrial primary production processes, or photosynthesis.

Biofuels can be divided in to two categories of first-generation and second-generation:

  • First generation describes biofuels that are derived from the edible parts of plants. A consideration associated with this form of biofuel is that large-scale production involves the mass cultivation of crops (such as maize) that could be otherwise be inputted into the global food system. Valuable resources such as arable land are thus prioritized for fuel production, rather than food production.
  • Second generation describes biofuels that are derived from non-edible parts of plants, such as woody stems, branches, etc. or from fruits that are not a part of the human diet. A benefit associated with second generation biofuels is that, unlike first generation processes, production is not inversely related to global food system production. Second-generation biofuel can be further divided in 2+ generation-biofuels and 2++ generation-biofuels
    • 2+ generation-biofuel production involves no use of arable land at all for energy production (i.e. algae fuel)
    • 2++ generation-biofuel production involves no use of arable land at all for energy production and no air pollution (this still occurs with the other biofuels, although there are no carbon emissions). (i.e. biohydrogen)

The Spring 2017 semester of ENGR215 Introduction to Design worked with Zane Middle School to design and build sustainable and educational infrastructure and apparatuses that supports K-8 STEAM education at their Eureka, CA location.

Selected quote


W. H. Auden

Thousands have lived without love, not one without water.

— W. H. Auden
More quotes...


Help us grow!

Appropedia is created by people like you! Feel free to contribute to Appropedia your original research, projects, current works, observations and wisdom. Improve articles by clicking "edit" on top of any page or section. Our philosophy is: BE BOLD and contribute!

Questions? Comments? Visit the Village pump or the Permies permaculture forums.

Facebook Pinterest Twitter Flickr YouTube

This article is issued from Appropedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.